1. Field of the Invention
The invention relates to the field of measuring, controlling and treatment instruments, such as for example instruments for measuring the temperature of a surface at a distance, which utilise a laser-generated beam for the purpose of striking a surface or other target and thereby indicating to the user that the instrument is properly aligned. It is known in the art of laser-aimed instruments to project a single, i.e. central laser beam to create a spot of laser light on the target at a desired central point of the area of the target under investigation or treatment.
It is also known in the art of laser aimed instruments to utilise a beam splitting means which causes a single laser beam to be split into a plurality of beams which are, for example equally spaced about a central axis and at the same radius from the axis, so that a plurality of light spots are formed on the target around an area of the target and can serve to outline that area for investigation.
When a single laser beam is used for the production, by splitting, of a plurality of spaced beams to form a pattern on a target, there is diminishing of the intensity of the split beams which become very much dimmer after a single generated laser beam is subsequently split, e.g. as by a diffraction beam splitter. Thus a single central beam may well be sufficient in intensity to illuminate a central spot on a target at a distance, but if that same single laser beam is split into, for example, twelve fractional beams intended for producing a pattern of spots of light on the target, the intensity of those fractional beams will be only about one twelfth of that of the single central beam. Thus, at a comparable distance from the laser the fractional beams may be difficult or impossible to see by the user of the instrument, particularly in poor ambient light conditions.
The invention further relates generally to the projection of laser beams for the directional aiming of apparatus, such as radiometer instruments, which may be used for ascertaining the temperature of a surface using infra-red measurement techniques, and more particularly to such apparatus which utilises a laser sighting device which is adapted to project one or more laser sighting beams onto a target for defining on the surface of the target an energy zone thereof, the temperature of which is to be measured.
It is necessary to be able to match the area-to-distance ratio needed to collect enough energy to activate a radiometer. For example, if an area-to-distance ratio is expressed as 20:1, it represents an energy zone diameter of one foot at a distance of twenty feet away at right angles. A less sensitive and less costly device may have an area-to-distance ratio of 6:1 where the diameter of the energy zone is one foot at a distance of six feet. The area of the energy zone is defined as where 90% of the energy is found and collected.
There can be times when the use of only a single laser beam is required, for example when it is desired to center a measuring apparatus with the center of a surface to be investigated.
There are also other instances where it is desired to define, on the surface to be investigated, points on the periphery of an area, such as a circle, and for this purpose there can be used a laser beam projector which is provided with a beam splitter device arranged to project, onto the surface to be investigated, a pattern of laser light spots arranged in, for example, a circle. Hitherto it has been necessary to utilise separate laser projection instruments for single-spot and multiple-spot projection systems, to permit the projection of any selected one of a number of multiple spot patterns.
2. Objects of the Invention
It is accordingly a primary object of the invention to provide an improved laser beam aiming, guiding or sighting means, for use in conjunction with a measuring or control instrument, which permits changing of the production of the laser beam from a smaller number of beams to a larger number of beams, and vice versa, from time to time such that the smaller number of beams, which are of relatively greater intensity, permit the user of the instrument to see where the smaller number of beams is striking the target, and more clearly because of the relatively greater beam intensity, and subsequently to utilise the larger number of beams to outline a desired area of the target, the general location of that area of the target being known to the user, even if the illumination by the larger number of beams is considerably fainter, because the user will have had the advantage of seeing the target area pinpointed by the smaller number of beams.
Another object of the invention is to provide a laser beam generating means, for use in conjunction with a measuring or control instrument, which permits changing of the beam production from a first state in which there is a single central beam of relatively greater intensity to a second state in which there is a plurality of fractional beams, of relatively lesser intensity, for example to outline an area of a target.
Yet another object is to provide beam splitter means which are readily movable at the will of the user for placing into and out of the line of a single laser beam.
Yet another object is to provide means for timed duration of projection of each display of laser beams.
Yet another object is to provide means for automatic alternation of different kinds of beam projection, such that the user has the target area essentially continuously and repetitively illuminated by the single central beam and the plurality of fractional beams defining an area of the target.
Yet another object is to provide the combination of a measuring, control, or treatment instrument and a laser beam projecting means having the characteristics set forth in the foregoing objects.
A still further object is to provide an instrument in which a switching means, serving to change the beam projection from a lesser number of beams to a greater number of beams, and vice versa, serves to cause projection of a number of beams which produce a desired pattern, which may be varied either at the will of the user, or from time to time automatically, or both, on a target area.
Yet another object of the invention is to provide a device which permits aiming, guiding, or sighting of a beam or beams for purposes other than temperature sensing purposes, such as for decorative and/or entertainment purposes, or activation of apparatus, or for health treatments.
According to a first aspect of the present invention there is provided a laser generating means, for use in conjunction with a measuring, controlling or treatment instrument, which permits changing, manually or mechanically or electronically, projected laser light from a lesser number, for example a single central beam, to a larger number of beams utilised to define an area of a target centered on the point defined by the single central beam.
According to a second aspect of the invention there is provided a measuring instrument, for example an instrument for measuring the temperature of a target situated at a distance from the measuring instrument, which includes thereon a laser generating means as set forth in the preceding paragraph.
According to a third aspect of the present invention there is provided a beam changing means, for a laser-generating instrument, which is in the form of a separable attachment.